The present disclosure relates to systems and methods for manufacturing 3D parts through a combination of electrophotography-based additive manufacturing processes and molding processes.
Additive manufacturing is generally a process in which a three-dimensional (3D) object is manufactured utilizing a computer model of the objects. A basic operation of an additive manufacturing system consists of slicing a three-dimensional computer model into thin cross sections, translating the result into two-dimensional position data, and feeding the data to control equipment which manufacture a three-dimensional structure in a layerwise manner using one or more additive manufacturing techniques. Additive manufacturing entails many different approaches to the method of fabrication, including fused deposition modeling, ink jetting, selective laser sintering, powder/binder jetting, electron-beam melting, electrophotographic imaging, and stereolithographic processes.
In an electrophotographic 3D printing or production process, each slice of the digital representation of the 3D part is printed or developed from powder materials using an electrophotographic engine. The electrophotographic engine generally operates in accordance with 2D electrophotographic printing processes, using charged powder materials that are formulated for use in building a 3D part (e.g., a polymeric toner material). The electrophotographic engine typically uses a conductive support drum that is coated with a photoconductive material layer, where latent electrostatic images are formed by electrostatic charging, followed by image-wise exposure of the photoconductive layer by an optical source. The latent electrostatic images are then moved to a developing station where the charged powder is applied to charged areas, or alternatively to discharged areas of the photoconductive insulator to form the layer of the charged powder material representing a slice of the 3D part. The developed layer is transferred to a transfer medium, from which the layer is transfused to previously printed layers with heat and/or pressure to build the 3D part.
In fabricating 3D parts by depositing layers of a part material, supporting layers or structures are typically built underneath overhanging portions or in cavities of objects under construction, which are not supported by the part material itself. The support structure is typically built utilizing the same deposition techniques by which the part material is deposited. The support material adheres to the part material during fabrication, and is removable from the completed 3D part when the printing process is complete.